Prior to the last several decades, teachers instructed students at one physical location, such as a classroom. The teacher was able to interact in person with the students, and was further able to check whether or not a student was following along with the lesson simply by watching the student and, if necessary, walking to the student's desk or other workstation. As conferencing and collaboration tools have evolved, so have teaching methods. Teaching can now be done online, allowing a teacher to instruct students who are physically located in diverse places using the Internet. Further, an online teacher can show students what he is doing on a screen in real time. With the advent of videoconferencing, the teacher is able display his computer screen with students so that students can follow what he is doing.